Try the left side of the instrument housing. Mine has a sticker with the model. After the model number is a -x to show revision.
check your purchase info my L5740 said -1 on the dealers invoice and some sticker I tossed. The only thing I have found is -3 have swivel seats and a pto knob.
I just got the -1 owners manual and I have the -3 too so I will read them both and let you know.
Try the left side of the instrutment housing. Mine has a sticker with the model. After the model number is a -x to show revision.